Pregnancy
Weeks pregnant
Days since the last menstrual period divided by seven, with the remainder reported separately as whole days.
The Formula
weeks = floor(days / 7)
Days since the last menstrual period divided by seven, with the remainder reported separately as whole days.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| w | Weeks | count | Whole weeks of gestation. |
| d | Days | count | Days since the last menstrual period. |
What Each Symbol Means
wcount
Weeks
Whole weeks of gestation.
dcount
Days
Days since the last menstrual period.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate how many weeks pregnant page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate How Many Weeks Pregnant, filed under Health. Every number the guide produces comes from substituting into this one line.